I have recently purchased an FT-950 and I am very interested in digital connectivity and control and especially analysis of the recieved and transmitted signals. This functionality seems to be covered in the DMU-2000 add-on hardware, which I do NOT want to purchase - I want to use my PC.

So far, I have already run HRD and PowerSDR programs on my PC and have sucessfully connected to the FT-950 with the serial port. Last night, I also connected the audio out to my PC soundcard (integrated, so probably not high enough bandwidth.) I think I used the REC Out port on the back of the FT-950. Anyway, I am able to control the rig and was able to see audio signals right around my frequency on the PowerSDR display. My question is, I am not fully sure what I am looking at or what my options are. I would like to be able to view signals over a larger portion of the band, similar to the DMU-2000 spectrum analyzer functionality. I would also like to view the recieved audio (which I guess I am seeing) and my transmitted waveform on an O-scope like display. I am wondering if I need to connect to a different place on the radio for these signals, specifically to see the spectrum analysis and transmitted signal. Am I using the most approprate software to view these features?

I am sure I will need a better sound card, and it looks as though one of the external USB interfaced ones would be a good place to start. Any advise here would be good, too. (I will probably try some of the digital modes later, so one that supports those capabilities would be desired.) Anyway, thanks in advance for any advise or pointers.

You need to get the apples and oranges sorted out here! Looking at just the received audio is one thing - looking at a wide piece of the spectrum (greater than 5 KHz or so) is something else entirely. You have apparently connected your 950 audio out (not Rec Out) to your sound card. This allows you to look in detail at the signal you're tuned to, and that's it. You see nothing outside the IF passband of your receiver and how much you see depends on your receiver filter selection. A better soundcard will show you nothing more.

In order to see what's happening outside your filters, you need to be able to tap into the receiver's signal path at a point BEFORE filtering is done. That means looking the first IF (before any filter). You then need to convert that IF signal (which is RF, not audio) into something that the software can deal with and that usually means somehow converting it to wide-band audio (usually a max of 192 KHz width). That's what the LP-Pan hardware from N8LP does for you and that's where a good soundcard comes in. It needs to be able to properly deal with a wide bandwidth audio signal. Others have already determined which cards do that the best - see the LP-Pan documentation. One problem, however, is that the LP-Pan unit won't handle IF frequencies in the range (60-70 MHz) used by the Japanese manufacturers.

It appears that the 950 can use the DMU-2000, which is an entirely RF-based approach. RFSpace offers a special Yaesu interface for its SDR-IQ and SDR-14 SDR receivers that plugs into the 950's DMU-2000 connector. Those SDR receivers have a USB connection to the PC and special RFSpace software for display of the spectrum. The resultant display is similar to that of PowerSDR. Note that NO soundcards are involved in this at all, other than to listen to the signals on your PC if desired. The RFSpace units are full-fledged receivers which, in the case of use with the 950, are used to listen only to the 950's IF frequency (which the RFSpace interface must mix down to something below 30 MHz as their receivers top out there). Older Yaesu rigs, such as the FT-1000MP, don't have such an output and in that case the RFSpace receiver is connected to the RF Out jack, which is simply the antenna feed. The potential problem there is that the SDR receiver is receiving everything from 0 to 30 MHz at once (no tuned front-end) and so may easily overload if there are strong near-by signals, such as AM broadcast stations. Those SDR receivers feed the RF signals (now converted to I & Q audio signals) via the USB interface to the custom software for display.

I much prefer the PowerSDR or RFSpace software approach to a hardware spectrum display, even though it's much more complex to implement for the user. You have control over averaging and smoothing of the displayed signals and can get a much better view of signals than you can on a fast-response spectrum analyzer.

Also want to point out that PowerSDR expects a I/Q signal fed to it. So the non quadrature audio out of the 950 is not actually usable by PowerSDR.

In addition to the suggestion of the SDR-IQ and DMU alternative from RF Space, you may also want to consider a stand alone SDR that you feed the RX signal to before it goes into the 950. Perhaps the 950 has provisions to feed the RX signal out to another radio.

The upcoming Flex-1500 would be a good candidate for sub RX use in this fashion. It is less expensive than a DMU 2000 and can perform as a completely independent RX and QRP transmitter. It also has its own self contained A to D and D to A's so no sound card is needed for use.

Its kludgey but N8LP made a IF based RX system that works with the K-3 to gain something like what you want. Its called the LP-Pan. It runs about $200 and plus another $150 or so for the sound card. It can be adjusted to probably work with your radio if you have a pre-filter IF output in the 8 to 9 mhz range Google N8LP

The best experience would be to just buy a Flex radio. These legacy radios like the 950 are a poor substitute for a truly integrated SDR experience

I just got an FT-950, the EMU 1212M sound card, the IF-2000 interface, and LP-PAN, it was all very easy to hook up and get working, just had to get the latest version on the NaP3 software. The sound card was about $140, the IF-2000 $190 and the LP-PAN about $235, so about $250 cheaper then the DMU-2000 from Yaesu. I love having the 192 Khz display and waterfall display.

I use the SDR-IQ with my FT-2000 for a panadaptor. You can also use it independently with it's own antenna and a laptop as a free standing receiver when you are on the go, or testing an antenna as far as how it sounds to listen to in the woods.The SDR-IQ as a panadaptor is far superior to the DMU system visually and in flexibility.

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